This invention relates to frames for doors and to the frame members from which said frames are assembled.
At present, the majority of door frames are made of wood and include a pair of jamb members and a header. If it is an outside door, the door frame also includes a door sill while in the case of inside doors the jambs extend to the floor.
Where large volumes are involved, the door frame members can be manufactured at a factory ready to be assembled on the job site or, in some instances, at the factory. Frequently, however, the door frame members are cut from lumber on the job site and drilled and routed out to provide for keepers and hinge mounting areas and then fitted into position for each individual door.
In addition to wood, there are door frames of other material or of other material along with wood.
U.S. Pat. No. 1,606,780, issued Nov. 16, 1926, discloses a metal door frame.
U.S. Pat. No. 4,281,481, issued Aug. 4, 1981, discloses an aluminum door frame while U.S. Pat. No. 3,287,856, issued Oct. 16, 1964, discloses an extruded metal frame.
U.S. Pat. No. 4,531,337, issued Jul. 30, 1985, discloses a combination metal and wood door frame while U.S. Pat. No. 4,505,080, issued Mar. 19, 1985, discloses a combination door frame of extruded metal or plastic and wood while U.S. Pat. No. 5,293,723, issued Mar. 15, 1994, discloses a combination of plastic and wood door frame.
In the case of wood door frames not only is wood relatively expensive but the wood members from which the frame is made are subject to twisting and warping adversely affecting the accuracy of the frame.
The metal frames on the other hand do not lend themselves to adjustment in the field to meet the circumstances of the frame receiving openings in the wall. Moreover, they are expensive and also usually involve assembly with some wood. Moreover, the metal is a good conductor of heat and is therefore a poor insulator.
Extruded plastic frame members do not have the inherent strength or wood and are not readily secured without the use of wood inserts.
European Patent Application 0-586213 A1, published Sep. 3, 1994, discloses a hollow window or door structural component which can be extruded or injection molded from a polymer and wood fiber. However, being extrudable, the walls of the hollow component have uniform dimensions throughout their length and the component is open at the ends. Such components can be joined at right angles by diagonally cutting and welding the ends thereof but provide no interfitting seating arrangements.
U.S. Pat. No. 4,154,034, issued May 15, 1979, discloses door frame. components of generally J-shape cross-section molded from fiber glass reinforced polystyrene. However such components rely on the upturned tip of the lower part of the J as a door stop and use the back of the J for mounting metal strips for attaching the component to the studding.
The present invention is directed to providing a door frame which is very much cheaper than existing door frames, exhibits all the advantages of solid wood frames for workability and insulation but which is stronger, impervious to the elements and insects and will not splinter, crack, warp, corrode or rust, nor require the maintenance involved with wood frames.
According to the invention, the door frame is formed from components of compression molded composite material molded into accurate profiles ready for quick, easy and accurate assembly.
More particularly, according to the invention the frame components are compression moldings of filler, waste, or recycled particles or small pieces (hereinafter xe2x80x9cparticulate materialxe2x80x9d) bonded together by a thermoplastic material which can be a waste or recycled thermoplastic.
Such compression molded components according to the preferred form of the invention are formed to provide interengaging locating means to ensure that they are brought together in precisely accurate registration ready for securement by appropriate fasteners.
In this connection, by providing for precise component assembly interengagement a minimum number of fasteners is required to secure the frame members in assembled relation enabling the door frame to be quickly, easily and accurately assembled.
Being molded, the invention enables the jamb and header frame members to be formed as elongated channels or boxes suitably internally reinforced which present stepped bottom surfaces to be presented facing inwardly of the door receiving opening to be framed by the door frame. Such in effect hollowed outdoor frame members thus require a minimum of material creating members of light weight for ease of handling and installation.
Further, by compression molding the frame members, they can be formed to provide integral bored pods, protuberances or thickened areas to receive, support and accommodate the passage of screws or the like therethrough to secure the frame members to the door frame opening.
Moreover, by forming the door frame elements in the molding or other operation provision can be made to accurately locate the hinge and striker plate mounting areas and to provide appropriately located internal reinforcing hollowed out pods or blocks of material to accept the insertion of the latching and bolting hardware of a door.
Also, according to the invention, the jambs and header members can be molded to produce a precisely accurate integral molding to meet the brick work (sometimes refined to a brick molding) when the door frame is for an outside door.
Where it is desired to employ a separate brick molding according to the invention, there is provided an elongated compression molded channel member with bevelled ends and transverse webs including webs running angularly or obliquely across between the walls of the channel and webs running perpendicularly across between the channel walls whereby the molding may be cut at appropriate locations to form bevelled ended header moldings of varying length depending on the door width and jamb moldings having bevelled upper ends either for a left hand or right hand door jamb.
Further according to the invention, the door frame sill where required is formed as a molded composite structure with a repeating internal pattern so that it can be cut at appropriate points to fit the width of door which the door frame is to receive.
These and other features of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.